SAN FRANCISCO , California -LRB- CNN -RRB- -- A wildfire threatened to decimate historic Angel Island , the largest in the San Francisco Bay , and a Marin County fire official warned it could take up to four days contain the blaze .

At 9:15 p.m. Sunday the fire was burning only on the southeast side of the island .

The fire , which began about 9 p.m. Sunday , had consumed about 250 acres of vegetation near the top of Mount Livermore 's 788-foot peak , Battalion Chief Mike Giannini said Monday .

iReporter Bob Austrian , 45 , of Tiburon , said he could see the blaze from his home about 4 or 5 miles from the island .

He noticed the blaze at 9:15 p.m. Sunday . It `` started as a little red glow '' on the southeast side of the island and worked its way over the top and around the side of Mount Livermore , he said early Monday morning . Watch the island burn ''

`` It 's still ripping right now , '' Austrian said at 5 a.m. , noting that the blaze posed `` quite a spectacle '' with the town of Belvedere in the foreground and the Bay Bridge that connects Oakland and San Francisco serving as a backdrop .

Fire crews and equipment were being ferried to the island to battle the blaze , Giannini said . About 200 firefighters were already involved in the effort or en route , he said .

None of the blaze is contained , and Giannini said he expects the firefighting effort to last for three to four more days .

Austrian , who has visited the island at least a dozen times , said he 's concerned that firefighters wo n't be able to douse the blaze . The island is mostly vegetation with a few historic buildings , foot trails and access roads . iReport.com : See , share images of the blaze

Even with the necessary manpower and firefighting resources , he said , it will be difficult to reach the actual blaze .

`` It 's just the saddest thing because there 's no way to stop it , '' Austrian said .

Fire officials said earlier that all of the park workers and campers on the island were safe .

Angel Island -- a hilly grass - and forest-covered island -- is the largest in San Francisco Bay .

The island was used as a quarantine station for immigrants suspected of carrying diseases starting in the late 19th century .

It 's now a place for hiking , biking , camping and boating .

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Blaze not contained , firefighting efforts could last four days , official says

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iReporter : `` It 's just the saddest thing because there 's no way to stop it ''

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Blaze burning vegetation near the top of Mount Livermore 's 788-foot peak

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All park workers , campers are safe , fire official says